Polyurethane Foam (image) Swiss Federal Laboratories for Materials Science and Technology (EMPA) Share Print E-Mail Caption This image shows polyurethane foam under an optical microscope. The flame retardant has no effect on the structure of the foam. Credit Empa Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.